Family risk factors predicting children's academic, social, and mental health adaptation during the transition to elementary school have received little systematic investigation. The proposed continuation study has two specific aims: (1) to extend our theoretical model of the mechanisms linking family processes and children's adaptation to elementary school, and (2) to extend our family-based preventive intervention model from couples groups for two-parent families to single- parent groups for mother-headed families. We have been developing a 5-domain conceptual model linking family risk and children's adaptation. Results of our current study show that parents who participate in couples groups focused on modifying these risk factors before their first child enters kindergarten improve their marital and parenting quality and their children improve in academic achievement, social adaptation, and lower levels of behavior problems in Grade 1. This application requests 5 years of support for two continuation studies. Study 1 will follow 100 of the current 118 families when their first children are entering Grade 4 - a middle childhood transition that involves shifts in cognitive, social, and school curriculum complexity. This study will enable us to (i) evaluate the longer-term effects of our early intervention, and (ii) examine the cumulative risks and buffers in students' family environments as they approach the threshold of adolescence. Study 2 extends our intervention model to a broader range of families of children entering elementary school. Adapting our couples group intervention to groups for 120 single mothers (divorced and never married) will also allow us to compare paths to academic and social competence in single- and two-parent families. Results of the proposed studies will contribute to prevention research by: (1) describing the mechanisms by which family risk and protective ape children's adaptation to early and mid-elementary school; (2) determining the impact of pre-kindergarten family-based interventions on children's school adaptation; and (3) identifying features of the intervention that are responsible for change in the couple. in the parent-child relationships and in the child. This study expands the usual focus of family/school studies from mothers and children to father-child and family observational data. It combines longitudinal and intervention methods to examine the family mechanisms contributing to adaptation during a major family transition. The significance of the study lies in its theoretical and practical goals of examining the links between individual, dyadic, and systemic measures of family functioning, and children's achievement, peer relationships, and behavior problems in the early years of elementary school. These outcomes constitute the most important risk factors for both academic and mental health problems in late adolescence.